Crimping mechanism



Aug. 22, 1961 w. A. MEnER mmm; mcmmsm 3 Sheets-Sheet l Fed Sept. 17.1958 v 011 Wi A. Mier ,WMI/,nBM/lj 4 TTRNEYS Aug. 22, 1961 w. AJMEIER2,996,939

CRIMIPING MECHANISM Filed Sept. 17, 1958 3 SheetsSheet 2 INVENTOR.

Z'IZm A. Meier A TTOENE YS All@ 22 1961 w. A. MEIER 2,996,939

ma Mmmm Filed sept. 17, 1958 3 Smeets-sheet 5 HTTORNEYS 2,996,939 CINGMECHANISM William A. Meier, Roselle, Ill., assigner to Signode SteelStrapping Company, Chicago, Ill., a corporation of Delaware Filed Sept..17, 1958, Ser. No. 761,582 2 Claims. (Cl. {S1- 9.1)

The present invention relates to tools for crimping a seal aboutoverlapped strap ends and more particularly to power-operated hand toolsand to a new linkage for operating crimping jaws upon the longitudinalor translational movement of a power source mechanism toward and awayfrom the crimping jaws.

In accordance with the present invention, the tool has a pair ofcrimping jaws formed at the ends of a pair of jaw links which arepivotally mounted in spaced opposed relation in an H-shaped crimpingblock or notcher. 'I'he jaw links are pivotally secured at the rearwardends thereof to a pair or rst pair of operating links, respectively. Theterm lower links is used herein to designate this rst pair of operatinglinks. A second pair of operating links employed in the instantmechanism is herein described as upper links.

The rear ends of the jaw links are pivotally connected to the lowerlinks,`respectively, at intermediate points along the length of thelower links and the lower links are pivotally connected together at theforward end thereof.

A pair of upper or rearward links are connected to be responsive to the`longitudinal movement of a powerdriven operating rod for the purpose ofspreading the rearward ends of the lower links to spread the points ofconnection between the lower links and the crimping jaws or jaw linksapart to operate the jaws with an increasing mechanical advantage as theoperating rod approaches the end of its stroke completing the crimpingor sealing operation. The rearward ends of the upper links are pivotallyconnected to the forward end of the operating rod, and the forward endsof the upper links are pivotally connected to the lower links at therearward ends thereof, respectively. Thus, the interconnection betweenthe power source and the crimping jaws is a three or triple-linkconnection arranged to provide an increasing mechanical advantage as thejaws are moved toward each other.

The invention provides a simple, hand-operable, poweroperatedpistol-type crimper which facilitates effective crimping of a seal aboutoverlapped strap ends with minimum effort. The increase in mechanicaladvantage which is achieved minimizes the power requirement to permitthe completed tool to be operable with generally available and safepower supplies such `as hydraulic or pneumatic pressures, or an electricdrive, and to be of such size and weight as to facilitate convenienthand manipulation while at the same time providing a durable tool ofhigh crimping power.

The invention will be more fully described and its advantages willbecome more fully apparent from the following description of anillustrative embodiment of the invention taken in conjunction with theaccompanying drawing in which:

FIGURE l is a side elevation with parts broken away for clarity;

FIGURE 2 is a top plan View with parts broken away for clarity;

FIGURE 3 is a fragmentary vertical sectional view taken substantiallyalong the line 3-3 of FIGURE 2;

FIGURE 4 is a horizontal sectional view taken substantially along theline 4 4 of FIGURE l but showing the tool in crimping position;

FIGURE 5 is a fragmentary front elevational view; and

arent ice FIGURE 6 is a fragmentary perspective view illustrating thelinkage and including a part of one of the side plates exploded awayfrom the linkage to illustrate the assembly of the linkage between theside plates.

There is shown in FIGURE 1 an illustrative embodiment of the inventionin the form of an yair-operated pistol-type crimping tool identiedgenerally by the numeral 11i. The crimping tool *10 comprises a handgrip 11, having a trigger 12, and supporting an air cylinder 13. Theforward end of the cylinder 13 is closed by a mounting plate 14 which isprovided with a pair of forwardly extending mounting lugs 15 and 16. Themounting plate 14 is secured to the cylinder 13 by means of screws 17.

A pair of side plates 18 and 19 are secured to the mounting lugs 15 and16 by means of bolts 20 which extend through the side plates 18 and 19and through the mounting lugs 15 and l16, the bolts Ztl being receivedin nuts 21. The side plates 18 and 19, mounted as indicated above,extend forwardly of the mounting plate 15 in spaced apart parallelrelation. A-t the forward end of the side plates 1S and 19 and mountedtherebetween is an H-shaped crimping block or notcher 22. The notcher 22is formed to dene .a pair of side recesses 23 and 24 within which thejaw links 25 and 26 having crimping ja-ws 25' and 26 formed lat theforward end thereof, are mounted for pivotal movement by means ofnotcher pins 27 and 28 positioned adjacent to the crimping jaws 25 and26.

The central portion of the mounting plate 14 is formed with an inwardlyextending spring mount 30 which is externally recessed as indicated at31 for the purpose of receiving the enlarged forward end of -a pistonrod 32 that extends axially of the air cylinder 13. The rear of thepiston rod 32 is secured to a piston 33 lby a threaded interconnectionindicated by the numeral 34. The rear of the piston 33 abuts a flexiblediaphragm 35 which is secured at the rear of the air cylinder 13 by aretainer plate 36 formed with an externally projecting portion 37 havingthreads 38. The threaded projection 37 and the retainer plate 36 areheld in position at the rear of the air cylinder 13 by means of the jamnut 39. The projection 37 terminates in a slot 40 enabling rotation ofthe retainer plate 36 for adjustment purposes. A seal 41 surrounds theinner end of the projection 37 to render the joint air-tight.

The center of the retainer plate 36 is bored to provide a port 42 whichcommunicates with an air passage 43 running along the underside of theair cylinder 13 and into the hand grip 11. An air hose 29, extendingfrom a source of air pressure is connected to the pistol grip 11. Thepassage 43 communicates with a valve mechanism operated by the trigger12 to permit air to ow from the hose 29 into the mechanism.

When air enters the port 42 (see FIGURE 2) it acts against the`diaphragm 35 and propels the piston 33 along the air cylinder 13 intothe position shown in FIGURE 4 compressing a spring 44 surrounding thespring mount 30. When the air pressure behind the llexible diaphragm 35is removed as by venting to the atmosphere, the spring 44 will propelthe piston 33 rearwardly along the air cylinder 13 to the position shownin FIGURE 2. 'Phe piston rod 32 connected to the piston 33 is movedaxially with the piston; the forward axial movement of the piston rod 32being effected under air pressure to constitute a power-crimping strokeand the rearward axial movement of piston rod 32 being effected by thespring 44 for the purpose of opening the crimping jaws 25 and 26 so thatthe tool may be removed from the work.

The linkage which enables the longitudinal reciprocation of the pistonrod 3.2 to be transformed into an eiective opening and closing movementof the crimping jaws 25' and 26 is shown most clearly in the perspectiveillustration in FIGURE 6. In FIGURE 6 the crimping jaws 2S' and 26 areshown partially closed and the piston rod 32 is moved partially forwardin its power crimping stroke. FIGURES l, 2, 3 and 5 show the crimpingjaw actuating linkage with the crimping jaws in open work-receivingposition. FIGURE 4 illustrates the linkage with the crimping jaws 25 and26 in their closed or sealing position.

Referring more particularly to the perspective view of FIGURE 6, it willbe seeen that the jaw links 25 and 26 on which the crimping jaws 25 and26 are formed, are mounted for pivotal movement in the notcher 22 bymeans of notcher pins 27 and 28 which extend across the recesses 23 and24 and through the jaw links 25 and 26 close to the jaws 25 and 26'. Thenotcher pins 27 and 28 also extend into the side plates 18 and l19 and,more particularly, into the openings 45 therein. The notcher 22 isfurther provided with threaded openings 46 which receive screws 47 whichextend through openings 48 in the side plates 18 and 19. The screws 47do not extend into the side recesses f23 and 24 and are employed tobolster the securement of the notcher 22 to the side plates 18 and 19.

The trailing ends of the jaw links 25 and 26 are secured to lower links49 and 50, the preferred construction utilizing a pair of lower linksfor each of the jaw links 25 and 26. The jaw links 25 and 26 arepivotally secured to the lower links 49 and 50, respectively, at pointsintermediate the length of the lower links by jaw link pins 51 and 52extending through the lower links 49 and 50 and the jaw links 25 and 26.

A washer 53 is positioned adjacent one of the lower links 49 and awasher 54 is positioned adjacent another of the lower links 50 to ll thespace between the links 49 and 50 and the interior surfaces of the sideplates 18 and 19. This space occurs due to the staggered offsetarrangement of the links as discussed below.

The lower links 49 are staggered with respect to the lower links 50 dueto the fact that lower links 49 and lower links 50 are all pivotallyinterconnected by a common pin 55 at the forward end of the links. Inview of the staggered position of the links 49 with respect to the links50, the jaw link 26 is provided with an offset 56 at the rearward endthereof, whereas the jaw link 25 is provided with a similar offset 57which faces in a direction opposite to the direction in which the offset56 extends.

The rearward ends of the lower links 49 embrace the forward end of upperlink 58 and are pivotally connected to the upper link 58 by means of thepin 59. Similarly, the rearward ends of the lower links 50 are pivotallyconnected to the forward end of upper link 60 by means of pin 61. Therearward ends of the upper links 58 and 60 are recessed as indicated at62 and 63 to permit these upper links to mesh together. The rearwardends of the upper links are pivotally connected together in theyokeshaped forward extremity 64 of the piston rod 32 by means of the pin65.

When the piston rod 32 is fully retracted, the forward extremities ofthe lower links 49 and 50 are adjacent to the notcher 22 and the notcheris provided with a cutout portion 66 to receive the forward ends of thelower links 49 and 50. Similarly, when the piston rod 32 is fullyprojected, as illustrated in FIGURE 4, the trailing ends of the jawlinks 25 and 26 are adjacent to the upper links 58 and 60 and the upperlinks 58 and 60 are provided with cutout portions 67 and 68.

The pin 55 which interconnects the forward ends of the lower links 49and 50 extends beyond these links and into a central longitudinallyextending channel 69 in each of the side plates 118 and 19 so thatmovement of the pin 55 is confined to a longitudinal movement within theopposed channels 69. This insures that the projection and retraction ofthe piston rod 32 will produce a smooth opening and closing movement ofthe crimping jaws 25 and 26'. The manner in which the guide pin 55 islimited to movement along the longitudinal channel 69 is illustrated inFIGURES 2, 3 and 4.

One of the important aspects of the invention lies in the linkagearrangement by which at the beginning of the stroke as shown in FIGURE2, the mechanical advantage obtained by the piston rod 32 is limited,whereas toward the end of the stroke as shown in FIGURE 4, themechanical advantage achieved is very large since the lower links 49 and50 and the upper links 58 and 60 are almost perpendicular to the pistonrod 32. Since the mechanical advantage increases as the links 49, 50, 58and `60 become further and further removed from the position shown inFIGURE 2, in which these links are substantially in alignment with thepiston rod 32, it will be apparent that the mechanical advantageprogressively increases as the crimping jaws 25 and 26 are closed. Thus,the greatest mechanical advantage is achieved at the end of the strokewhen the full resistance of the seal to the crimping action takes placeand when the momentum of the forward movement of the piston rod 32 canbe of assistance to the completion of the sealing operation. As can beseen in FIGURE 4, the guide pin 55 moves rearwardly along the channel 69toward the yoke 64 during the power crimping or sealing stroke.

The notcher 22 is desirably formed as a single piece in which the siderecesses 23 and 24 are separated by an intermediate section 70 which isintegral with the wings 71 and 72, the wings 71 and 72 and theinterrnediate portion 70 together defining the recesses 23 and 24.

In the form of the invention which has been illustrated, the jaw links25 and 26 and the jaws 25 and 26 move in a plane which is perpendicularto the plane of the hand grip 11. It will be appreciated that the screws17 securing the mounting plate 14 to the air cylinder 13, may be removedand the operating end of the tool rotated 90 in either direction so thatthe crimping jaws 25' and 26 will operate in the plane of the hand grip11. After pivoting of the mounting plate 14 with its associatedstructure, the screws 17 are replaced. Thus, the crimping tool may beadjusted so that the crimping jaws will move either in the plane of thehand grip 11 or in a plane at right angles to the plane of the hand grip11.

The air passage 43, as illustrated in FIGURE l, extends from itsconnection with the port 42 downwardly through a web 73 to the rear ofand beneath the air cylinder 13 and into the hand grip 11. The valvemechanism which controls the fiow of air from the supply hose 29 to thepassage 43 is operated by a trigger 12 at the upper front portion of thepistol grip 11. The trigger 12 is pivotally connected to the upper endof the hand grip 11 by means of the pin 74 which extends between a pairof ears 75 (see FIGURES l and 5) dening a trigger-receiving recess 76.Washers 74' mounted on pivot pin 74 lare employed to centrally positionthe trigger 12 in the recess 76 and to reduce friction. Movement of thetrigger 12 which is normally biased to a closed (counterclockwise, asviewed in FIGURE l) position, is limited by the stop pin 77 whichengages a rearwardly extending abutment 78 at the lower rearward end ofthe trigger.

The lower end of the hand grip 11 is bored to define a valve receivingbore 79 which comprises an upper valve stem-receiving bore 80communicating with the triggerreceiving recess 76 and a lower largerdiameter bore 81 within which the valve mechanism is mounted. The bore81 communicates with the air passage 43 as indicated at 82.

The valve mechanism includes a valve stem cap 83 which is slidinglyreceived within the bores 80 and 81 and comprises an upper rod portionand a polygonal (in this instance, triangular) flange 85 on the lowerend of the upper portion 84. A valve stem 86 having an upper flange 87and a lower flange 88, is coaxially secured to the underside of theflange 85 as by a threaded connection. A valve extension 89 having apolygonal acarrear;

(in this instance, triangular) iiange 90 at the upper end thereof iscoaxially secured to the valve stem 86 below the flange 88 by a threadedconnection.

Threadingly received within the bore 81 is a valve housing 91, securedin place by the threaded connection 92. The air hose 29 is secured tothe rvalve housing 91 by means of connector 93 and the reducing bushing94. The valve housing 91 is formed with a lowermost portion defining arecess 95. The lowermost portion of the housing 91 is secured to thebore 81 by the threaded connection 92. The valve housing 91 furtherincludes an uppermost portion defining a recess 96 within which theflange 85 of the valve stem cap 83 is slidingly received. Between theupper and lower portions, the valve housing 91 is radially bored toprovide ports 97 which communicate with the air passage 43.

The ponts 97 are bored in an intermediate portion of the valve housing,which portion is provided with upper and lower flange faces that operateas air outlet and air inlet valve seats 98 and 99, respectively. Theseseats 98 and 99 yare cooperatively arranged with valve gaskets orwashers 100 and 101 which are formed of a resilient material and which,when pressed against the valve seats 98 and 99, respectively, provideeffective seals therewith. The air outlet washer 100 is retained betweenange 85 on the stern cap 83, and the upper flange 87 on the valve stem86. The air inlet washer 101 is retained between the flange 90 on thevalve extension 89, and the lower flange 88 on the valve stem 86. Aspring 102 disposed between the flange 90 and the bushing 94 and withinthe lower recess 95 in the valve housing 91 normally biases the valvetoward a closed position with the washer 1 sealingly engaging the seat99.

The valve mechanism described above is operated by manipulation of thetrigger 12. When the trigger is moved in a clockwise direction about thepivot pin 74, as viewed in FIGURE 1, the lower rearward end portion 78thereof pushes against the upper end of the valve stern cap 83 causingthe cap, stem and extension of the valve to move dovmwardly against theforce of the biasing spring 102. This unseats the washer 101 from theseat 99 thereby permitting air to flow from the hose 2.9 through theconnector 93, past the sides of the flange 90 and through the passages9`7, 82 and 43 to the piston in the body of the tool to cause operationof the tool in the manner described above. At the same time that theinlet valve comprised of the Washer 101 and the seat 99, is opened, theoutlet valve, comprised of the washer I100 and the seat 98, is closed.

After the operation of the tool has been completed to crimp a sealdisposed about a pair of overlapped strap ends, the trigger 12 isreleased. This permits the spring 10'2 to move the valve cap, stern andextension upwardly to open the outlet valve and to reclose the inletvalve. When the outlet valve is open, air escapes from the piston andcylinder by passing through the ports 97, past the cap flange 85 andpast the cap rod 84 to exhaust through the bore 80. The spring 44 iseffective to drive the piston rearwardly of the body of the sealermechanism to drive the air in the cylinder out of the cylinder throughthe port 42.

From the foregoing it Will be readily observed that numerous variationsand modifications may be effected without departing from the spirit andscope of the novel concepts and principles of this invention. It will beappreciated that the above description and the accompanying illustrationof an illustrative embodiment of this invention is for the purpose ofproviding a complete desoription of the invention and that no specificlimitations on the invention are intended thereby.

I claim:

l. An air-powered hand tool for crimping a seal about overlapped strapends comprising a hand grip including a trigger, an air cylinder mountedatop said hand grip and terminating in a mounting plate, a valveoperated by said trigger and communicating with said air cylinder at therear thereof, a pair of spaced apart parallel side plates secured tosaid mounting plate and extending forwardly therefrom, a notchercomprising wings separated by an intermediate section defining a pair ofside recesses, said notcher being secured between the forward ends ofsaid side plates by securing means extending between said side platesand said wings, a pair of jaw links having crimping jaws thereon, saidjaw links being received within the side recesses of said notcher andpivotally secured Ibetween the wings thereof adjacent to the crimpingjaws for opening and closing movement between said side plates in aplane parallel to the plane thereof, a pair of lower links pivotallyinterconnected to each other at the forward end thereof Iby means of apin extending beyond said lower links, the interior surfaces of saidside plates each fbeing formed with a longitudinal channel receivingsaid pin to permit said pin and the lforward ends of said lower links tomove toward and away from said notcher -in a laterally confinedlongitudinal path, said lower links being pivotally connected with therearward ends of said jaw links at points intermediate the -length ofsaid lower links, a pai-r of upper links pivotally interconnected at therearward ends thereof and with the forward ends of said upper linksbeing pivotally connected to one of said lower links at the rearwardends thereof, a piston rod extending through said air ycylinder and intothe space between said side plates and secured to said upper -links atthe rearward ends thereof, said piston rod being secured to a pistonslidable within said `air cylinder so that said piston may be propelledby air pressure upon operation of said trigger to move said piston rodaxially toward said notcher to close said jaws with an increasingmechanical advantage, and spring means mounted between said mountingplate and said piston for retracting said piston and to open said jaws,the rear of said notcher being cut out to receive the forward ends ofsaid lower links when said piston rod is retracted.

2. An air-powered hand tool for crimping a seal about overlapped strapends comprising a hand grip including a trigger, an air cylinder mountedatop said hand grip and terminating in a mounting plate, a valveoperated by said tri-gger and communicating with said air cylinder atthe rear thereof, a pair of spaced apart paralled side plates secured tosaid mounting plate and extending forwardly therefrom, a notchercomprising wings separated by an intermediate section defining a pair ofside recesses, said notcher being secured `between the forward ends ofsaid side plates by securing means extending between said side platesand said wings, a pair of jaw links having crimping jaws thereon, saidjaw links being received within the side recesses of said notcher andpivotally secured between the Wings thereof adjacent to the crimpingjaws for opening and closing movement between said side plates in aplane parallel to the plane thereof, a pair of lower links pivotallyinterconnected to each other at the forward end thereof by means of apin extending beyond said lower links, the interior surfaces of saidside plates each being formed with a longitudinal channel receiving saidpin to permit said pin and the forward ends of said lower links to movetoward and away from said notcher in a laterally confined longitudinalpath, said lower links being pivotally connected with the rearward endsof said jaw links at points intermediate the length of said lower links,a pair of upper links pivotally interconnected at the rearward endsthereof and with the forward ends of said upper links being pivotallyconnected to one of said lower links at the rearward ends thereof, apiston rod extending through said air cylinder and into the spacebetween said side plates and secured to said upper links at the rearwardends thereof, said piston rod being secured to a piston slidable withinsaid air cylinder so that said piston may be propelled by air pressureupon operation of said trigger to move said piston rod axially towardsaid notcher to close said jaws with an increasing mechanical advantage,and spring means mounted between '7 said mounting plate and said pistonfor retracting said piston and to open said jaws, the inner faces ofsaid upper links 'being cut out to receive the rearward ends of saidcrimping jaws when said piston rod is projected.

References Cited in the le of this patent UNITED STATES PATENTS 8Freedom Nov. 2, 1954 Gregory July 3, 1956 Lngle Apr. 22, 1958 FreedomMay 26, 1959 FOREIGN PATENTS Germany Mar. 27, 1892 France June 3, 1957

